Isn't it fun trying to isolate and eliminate ground loop hums. As you have probably read here before, the type of hum you describe is usually, but not always, related to the cable TV signal (assuming you have cable TV). The cheapest first solution is to go to Radio Shack and buy a ground breaker -- the Shack sells one for about $15. Try that first and see if it works. If that does not solve the problem, your problem may be with the interconnect cabling. According to one of the local high-end HT dealers, it seems that some IC's have a different ground configuration than others, and thus there may be interaction problems betweeen SOME IC's and SOME equipment. You may have to try different cabling to see if that solves your problem. The idea you propose may also solve the problem, but you might want to try the quick alternatives first.
